Orange County California has two sets of toll roads, a 51 mile network run by transportation corridor agencies, and the well known 91 Express lanes. Both were built as a response to congestion and ever growing demand, but according to the L.A. Times the recession has hit demand on both sets of routes.
Some former users are more concerned about saving money instead of time, preferring to use money to buy fuel and food, instead of time. The report states:
From the beginning of the economic decline in 2007 through the fiscal year that ended in June 2010, trips were down 19% on the San Joaquin Toll Road, the portion of the 51-mile system known as California Highway 73. On the system's Foothill and Eastern toll roads, which include California Highways 241, 261 and 133, trips declined 17% in the same period, according to the Transportation Corridor Agencies.
Still none of this means that the roads are a failure, just that the value of time drops when both congestion on other routes declines and the need to save money offsets saving time. It is like demand for other goods and services, but the key issue here is that there are untolled alternatives.